The present invention relates to spring coiling machines in general, especially to automatic spring coiling machines. More particularly, the invention relates to improvements in spring coiling machines of the type wherein a tool, e.g., a so-called pitch selector tool, is movably mounted in or on the machine frame and is adjustable in response to rotation of a cam through the medium of a linkage which derives motion from the cam. Still more particularly, the invention relates to improvements in preferably automatic spring coiling machines of the type wherein the phase relationship of the cam with reference to the cycles of the machine is adjustable.
In conventional spring coiling machines of the above outlined character, the cam comprises a driven central portion which carries a lobe serving to determine the movements as well as the position of the tool following the start and preceding completion of the making of a coiled spring. The central portion of the cam carries detachable and adjustable segments which determine the nature or pattern of movement of a follower into engagement with and away from engagement with the aforementioned lobe to thus control the making of the foremost and rearmost portions of coiled springs. In other words, whenever the machine is to turn out a different spring or a different series of springs, the previously utilized segments must be adjusted or replaced until the operator is satisfied that the springs which are turned out by the machine match the desired norm. This entails considerable losses in time, as well as in valuable material of the springs, in addition to unnecessary wear upon various parts of the machine during adjustment of the segments and/or during replacement of previously used segments with fresh segments. The problem is aggravated if the machine is used for the making of short series of springs so that the aforementioned segments of the cam must be adjusted and/or replaced at frequent intervals. This can greatly increase the cost of each short series of springs and can entail considerable wear upon the machine at times when the machine is in the process of being set up for the making of a different series or batch of springs.